What are Hoàng đạo and Hắc đạo?
In Vietnamese and Chinese day selection, every day (and every hour) is assigned one of 12 rotating stars. Six stars are considered benevolent and make an auspicious day (Hoàng đạo, "yellow path"); the other six are malevolent and make an inauspicious day (Hắc đạo, "black path"). For big events such as weddings, business openings, groundbreaking or moving in, many people prefer a Hoàng đạo day.
The 12 stars
In rotation: Thanh Long, Minh Đường, Thiên Hình, Chu Tước, Kim Quỹ, Bảo Quang, Bạch Hổ, Ngọc Đường, Thiên Lao, Huyền Vũ, Tư Mệnh, Câu Trần.
| Star | Type | Traditional meaning |
|---|---|---|
| Thanh Long | Hoàng đạo | Azure Dragon; auspicious, considered suitable for many things. |
| Minh Đường | Hoàng đạo | Bright Hall, where the emperor held court; good for formal matters. |
| Thiên Hình | Hắc đạo | Heavenly Punishment; usually seen as unfavourable. |
| Chu Tước | Hắc đạo | Vermilion Bird; linked with quarrels and gossip. |
| Kim Quỹ | Hoàng đạo | Golden Chest; good for weddings and wealth. |
| Bảo Quang | Hoàng đạo | Also called Thiên Đức; precious light, good for many things. |
| Bạch Hổ | Hắc đạo | White Tiger; considered heavy, often avoided for big events. |
| Ngọc Đường | Hoàng đạo | Jade Hall; good for starting construction. |
| Thiên Lao | Hắc đạo | Heavenly Prison; seen as obstruction. |
| Huyền Vũ | Hắc đạo | Black Tortoise; linked with loss. |
| Tư Mệnh | Hoàng đạo | The deity of destiny; good for blessings and new beginnings. |
| Câu Trần | Hắc đạo | Hook and Chain; seen as entanglement and delay. |
The six Hoàng đạo stars are Thanh Long, Minh Đường, Kim Quỹ, Bảo Quang, Ngọc Đường and Tư Mệnh.
How a day's star is found
The star depends on the day's Earthly Branch and the solar-term month (the month starting at Lập xuân is the Dần month, not the lunar month; see The 24 solar terms). The day on which Thanh Long falls is set by the month, and the other stars follow in branch order:
| Solar-term month | Thanh Long on day branch |
|---|---|
| Dần, Thân | Tý |
| Mão, Dậu | Dần |
| Thìn, Tuất | Thìn |
| Tỵ, Hợi | Ngọ |
| Tý, Ngọ | Thân |
| Sửu, Mùi | Tuất |
Example: in the Dần month (from Lập xuân), a Tý day is Thanh Long, a Sửu day Minh Đường, a Dần day Thiên Hình, and so on. After 12 days it repeats, so every 12 days contain exactly 6 Hoàng đạo days; when the solar-term month changes the pattern shifts.
Auspicious hours
Each day has 12 two-hour periods and 6 auspicious hours, which depend only on the day's branch:
| Day branch | 6 auspicious hours |
|---|---|
| Tý | Tý, Sửu, Mão, Ngọ, Thân, Dậu |
| Sửu | Dần, Mão, Tỵ, Thân, Tuất, Hợi |
| Dần | Tý, Sửu, Thìn, Tỵ, Mùi, Tuất |
| Mão | Tý, Dần, Mão, Ngọ, Mùi, Dậu |
| Thìn | Dần, Thìn, Tỵ, Thân, Dậu, Hợi |
| Tỵ | Sửu, Thìn, Ngọ, Mùi, Tuất, Hợi |
| Ngọ | Tý, Sửu, Mão, Ngọ, Thân, Dậu |
| Mùi | Dần, Mão, Tỵ, Thân, Tuất, Hợi |
| Thân | Tý, Sửu, Thìn, Tỵ, Mùi, Tuất |
| Dậu | Tý, Dần, Mão, Ngọ, Mùi, Dậu |
| Tuất | Dần, Thìn, Tỵ, Thân, Dậu, Hợi |
| Hợi | Sửu, Thìn, Ngọ, Mùi, Tuất, Hợi |
Branch to clock time: Tý 23–01, Sửu 01–03, Dần 03–05, Mão 05–07, Thìn 07–09, Tỵ 09–11, Ngọ 11–13, Mùi 13–15, Thân 15–17, Dậu 17–19, Tuất 19–21, Hợi 21–23.
How to read it sensibly
- It is one factor among many. Day selection also weighs the twelve day officers, taboo days (Tam nương, Nguyệt kỵ, Dương công kỵ nhật) and harmony with the person's birth year.
- Hắc đạo does not mean "forbidden". Many people still act on Hắc đạo days; a Hoàng đạo day guarantees nothing.
- It is cultural belief, not science. There is no empirical evidence that auspicious days change outcomes. Treat it as tradition for reference; base important decisions (financial, health, legal) on practical judgement and professional advice.
- Books differ in how stars are assigned to days and hours. Âm Lịch VN follows the common method above.
What kind of day is today?
To pick a date for a specific activity and your birth year, use the day finder. For a whole month, open the calendar (a green dot marks Hoàng đạo days), or see the daily outlook per animal.